All posts tagged Warm Storm

Our lexicon of what’s considered to be normal weather does not include February days in which temperatures at a North Pole shrouded in 24-hour darkness cross into above freezing ranges. But that’s exactly what some of our more accurate weather models are predicting will happen over the next five days.

Another Unusually Warm and Powerful Storm

During this time, a powerful 950 to 960 mb low is expected to develop over Baffin Bay. Hurling hurricane force gusts running from the south and digging deep across the North Atlantic, Barents, and Arctic Ocean, the low is projected to drive a knife of 50-60 F above average temperatures toward the North Pole by February 5th.

(20-25 foot surf heading for the increasingly fragile sea ice in this February 4 wave model forecast. Note the 30-40 foot waves off Iceland and associated with the same storm system that is predicted to bring above freezing temperatures to the North Pole on February 5th. Image source: Earth Nullschool.)

These warm winds are predicted to bring above freezing temperatures to areas that typically see -20 to -30 F readings in February. They are expected to rage over a sea ice pack that is at record low levels. And if the storm emerges, it will hammer that same dwindling ice pack with 20 to 25 foot or higher surf.

(Arctic sea ice extent is presently at around 13 million square kilometers [bottom red line] — a new record low for this time of year. It should be around 15 million square kilometers and would be if the world hadn’t warmed considerably since the 1980s. Image source: JAXA.)

Not only do the storms bring warmer temperatures with them — a kind of heat wave that interrupts the typical period of winter freezing — they also drive heavy surf into a thinner and weaker ice pack. The surf, drawn up from the south churns warmer water up from the ocean depths. And the net effect can dissolve or weaken large sections of ice.

The presently developing event is expected to begin to take shape on February 4th, with warm gale and hurricane force winds driving above freezing temperatures near or over the North Pole on February 4th – 6th. To say that such an event, should it occur, would be practically unprecedented is the common understatement of our time. In other words, this is not typical winter weather for the North Pole. It is instead something we would expect to see from a global climate that is rapidly warming and undergoing serious systemic changes.

(February 5 GFS model run shows above freezing temperatures crossing the North Pole. Temperatures in this range are between 50 and 60 degrees [F] above average for this time of year. If the extremely warm cyclone event occurs as predicted, it will be a clear record-breaker. It will also further harm Arctic sea ice levels that are already in record low ranges. Image source: Climate Reanalyzer.)

Extreme Cyclone Beneath an Extreme Jet Stream

In the predicted forecast we see more of the extreme jet stream waves that Dr. Jennifer Francis predicted as an upshot of human-forced polar amplification (a condition where the poles warm faster than the rest of the globe under a larger warming regime). The particular wave in question for the present forecast involves a high amplitude ridge running very far to the north over Svalbard and knifing on into the high Arctic. The facing trough over Baffin Bay, Greenland, and North America is also quite pronounced and elongated. A feature that appears to want to become a cut off bubble of displaced polar air in a number of the model forecasts.

High amplitude Jet Stream waves during Northern Hemisphere winter as a signature of global warming are predicted by Francis and others to generate greater temperature and precipitation extremes in the middle latitudes. They are a feature of the kind of stuck and/or upside down weather we’ve been experiencing lately where temperatures in the Northeast have been periodically colder than typically frigid locations in Alaska. These flash freezes have, at times, faded back into odd balmy days in the 50s and 60s (F) before plunging back into cold. But the overall pattern appears to get stuck this way for extended periods of time.

(Very high amplitude ridge and trough pattern at the Jet Stream level of the circumpolar winds is thought by a number of scientists to be a feature of human caused global warming. One that is related to polar amplification in the Arctic. Image source: Earth Nullschool.)

Heat in the Arctic is driving sections of cold air south even as warm air invades through places like Alaska, Northeast Siberia, and the Barents Sea. But the main variables of this story are global heat, global warming, fixed extreme temperature and precipitation patterns, and warm air invasion. The winnowing streamers of cold air driven out over places like the U.S. Northeast are just a side effect of the overall warming trend. One that is starkly apparent in the very odd western warmth that has grown more and more entrenched with each passing year.

For Now, It’s Still Just a Forecast

As with any five day forecast, we can take this one with more than just a grain of salt at the present time. But such an extreme event is entirely possible during the present age of human-forced climate change. During late December of 2015, we identified a predicted major storm that ultimately drove North Pole temperatures to above freezing. At the time, that storm was considered unusual if not unprecedented. However, since February is typically a colder period for the North Pole region, a warm storm drawing above freezing air into that zone would be even more unusual. It would also be a feature of the larger trend of loss of typical seasonal winter weather that we’ve been experiencing for some time now.

5 FEB UPDATE: Storm and Heat a Bit Further South and East Than Predicted

A powerful warm storm in the 952 mb range did form and track across Greenland to exit over the Greenland Strait earlier today. The storm drove warm air far north, pushing above freezing temperatures past Svalbard and over the dark and frozen sea ice. It hurled gale force winds, hurricane gusts, and massive swells into the ice. But it did not push temperatures to above freezing at the North Pole as some models had earlier predicted.

Overall, total Arctic region temperature anomalies are predicted to range from 2.5 to 3.5 C above the 30 year average for the next few days. These are very warm departures. But not so warm as recent spikes in the range of 4 to 5 C above average for the region. In addition, there appears to be a tendency for powerful warm storms to continue to develop near Svalbard in the longer 5-15 day model runs. So the North Pole isn’t out of the woods yet for potential above freezing temperatures this February.

Temperatures over the Chukchi Sea are predicted to hit as high as 37 degrees Fahrenheit (2.9 C) on Wednesday and Thursday as a massive high pressure ridge building over Alaska pulls warm, moist Pacific air northward. These temperatures represent staggering warmth for this Arctic Ocean zone during March when temperatures are typically about 54 degrees F (30 degrees C) cooler.

Major Warm Wind Invasion for the Chukchi This Week

(Multi-day above freezing temperatures for the Chukchi sea predicted for later this week is not a normal event for early March. Unfortunately, warm wind invasions like this one have become more common as the globe has warmed up due to human fossil fuel emissions. Image source: Earth Nullschool.)

This recent warm wind invasion is one of many observed over the past five years in which enormous bulges in the Jet Stream have pierced deep into what was once a mostly impenetrable pall of winter chill hanging over the Arctic. It’s a new atmospheric condition associated with rampant fossil fuel burning. One that has produced considerable damage to the Arctic environment by reducing sea ice coverage, threatening key species, melting glaciers and thawing permafrost.

Such incursions of extreme warmth bear the obvious marks of a failing of Arctic cold brought on by human-forced climate change and have tended to generate significant spikes in overall Arctic surface temperatures during fall, winter, and spring. This week’s warm air invasion of the Chukchi is expected to help push readings for the entire region above the 66 degree north latitude line to 4.5 C (8 F) above average for this time of year. That’s a strong departure for this region during the month of March when the typically more uniform advance of warmth in the lower latitudes tends to strengthen the Jet Stream — locking in Polar winter conditions in the far north through about the middle of April.

Far above average Arctic surface temperatures extending from October of 2016 through March of 2017 have been triggered again and again by these floods of warm air rising up from the south. And the net effect on Arctic sea ice volume has been little short of devastating.

Arctic Sea Ice Volume Lowest Ever Recorded During Winter, Comparable to Summer Volumes of the Early 80s

Arctic sea ice volume for both January and February of 2017 are now far below past record low trend lines for this time of year. Present record low monthly values for this past February are around 17,000 cubic kilometers vs previous record lows for the month during 2013 at around 19,500 cubic kilometers. Last February’s sea ice volume average of 17,000 cubic kilometers is about the same sea ice volume measured at the end of melt season in September of 1981. In other words, sea ice volume in winter now is comparable to sea ice volumes during the summers of the early 1980s.

(Arctic sea ice volume has never been this low during winter time. Image source: PIOMAS.)

All the record warmth flooding into the Arctic during 2016 and 2017 has undoubtedly contributed to these new record lows for sea ice volume. And a cooling of the Arctic surface relative to recent record warmth during March and April could soften this worrying trend somewhat. To this point, it is worth noting that sea ice extent measures are now closer to past record low trend lines. So there has been some slightly more hopeful inching back to slightly less ridiculously abnormal measures. A more positive movement that will likely take a hit as Arctic temperatures are predicted to significantly warm again this week.

Weather is Variable, But the Underlying Trend Looks Pretty Bad

Weather, as we should note, can be quite variable and may bring a more pleasant surprise later in the month. However, despite this potential, sea ice states are looking as bad or worse than they ever have at the end of freeze season. And it is worth noting that less ice coverage and volume leaves more dark water open to absorb the sun’s springtime and summer rays and less ice to reflect it. Furthermore, post La Nina periods, as we are now experiencing, tend to flush more atmospheric and ocean heat into the Arctic. So, despite the variable nature of weather overall, we’re in a bit of a situation where the systemic trend odds of a noteworthy sea ice recovery toward more rational trend lines pre-summer 2017 aren’t looking very good.

Almost continuous warm, moist air invasions of the Arctic during fall and winter of 2016 and 2017 have resulted in the lowest sea ice refreeze rates on record. As a result, the amount of ice covering sections of the Northern Hemisphere ocean is now remarkably lower than during past comparable periods. In other words, we’ve never seen a winter in which Northern Hemisphere sea ice was so weak and reduced.

One key measure, sea ice volume, has shown particular losses when compared to past years. And even taking into account a long term trend of ice losses for the northern polar region that has been ongoing since the 20th Century, the 2016-2017 losses stand out like a flashing red indicator light. A trend directly related to the human-forced warming of our world through fossil fuel burning and related greenhouse gas emissions.

(Significant sea ice losses during the winter of 2016-2017 show up clearly in the above PIOMAS graph. PIOMAS is a model measure of sea ice volume. And as you can well see when looking at the red line at the left hand side of the graph, the departure from past years is currently quite large. Image source: PIOMAS.)

In the above PIOMAS graph we find that January sea ice volume averaged around 14,000 cubic kilometers. This reading is roughly comparable to the early July average for the period of 1979 through 2016 — a time when the Arctic saw continuous declines in sea ice. The present reading is also about 1,500 cubic kilometers below the previous record low for the month of January set in 2013. And anyone looking at the above graph can well see that the departure is significantly below the trend line (about 8,000 cubic kilometers below the falling 38 year average for this time of year).

It’s worth reiterating that these are the lowest sea ice volumes ever seen for this time of year in the Arctic. A new record that comes after consistent new record lows occurring throughout the past 38 year period.

(Warm storm invasions of the northern polar region that inject high heat content, ice-melting moisture and far above average temperatures into the High Arctic have been a frequent occurrence over recent months. By February 10, GFS models predict that another such storm will push temperatures to more than 30 degrees Celsius above average for the North Pole and surrounding regions. This will produce yet one more powerful blow to sea ice attempting to rebuild in the region. Image source: Earth Nullschool.)

After these events roar through, the Jet Stream is predicted to flatten somewhat — allowing cooler air to re-establish over the Central Arctic as warmer air invades the mid-latitudes. As a result, air temperature anomalies in the 66 N and above region are expected to fall back to a range of 1 to 2 C above average in the 7 to 14 day timeframe. Such a return to closer to normal conditions may allow for more short-term bounce-back toward previous record low ranges in the volume measure. But a much longer period of closer to average conditions would be required for a full recovery.

Overall, refreeze season tends to last until April. So some time does remain for a bit of recovery. And we have seen extent measures trend closer to past record lows over recent days. However, considering the massive losses experienced during fall-winter of 2016-2017, two months is unlikely enough time to produce a significant recovery even if cooling to more reasonable above average temperatures were to occur and remain in place for an extended period.

There are weather and climate records, and then there are truly exceptional events that leave all others in the dust. Such has been the case across Earth’s high latitudes during this last quarter of 2016… — Bob Henson at WeatherUnderground

The dramatic Arctic warmth and related damage to sea ice continued today. It’s a situation that Bob Henson at Weather Underground has aptly dubbed ‘the crazy cryosphere.’ But from this particular observer’s perspective, the situation is probably worse than simply crazy. It appears that we are now in the process of losing an element — Arctic sea ice — that is critical to the integrity of seasonality as we know it.

(Extreme Arctic warmth was drawn in by two warm storms — one running north from the Barents on November 14. Another emerging from Kamchatka on November 16 and 17. Warm storms have, during recent years, run up along high amplitude waves in the Jet Stream and into the Arctic during both summer and winter — with apparent strong impacts to sea ice [see NASA video below]. Image source: Climate Reanalyzer.)

On November 17, according to Arctic sea ice expert Zack Labe, the Arctic Ocean actually lost about 50,000 square kilometers of ice coverage. This would be odd on any given November day — which typically sees a trend of rapid freeze as the Arctic cools down into winter. But it is particularly strange considering that the Arctic Ocean is presently in a severe sea ice deficit of around 700,000 square kilometers below previous record lows. One that follows on the heels of both a very warm October and an exceptionally warm November for the Polar region of our world.

These losses occurred just one day before overall temperature anomalies for the climate zone above 66 degrees North Latitude went through the roof. For today, according to Climate Reanalyzer, temperatures for the entire Arctic spiked as high as 7.26 degrees Celsius above average. This occurred even as readings near the North Pole hit to near or above freezing in some locations.

(Warm Storm running up through the Fram Strait on November 14 — an event which flooded the high Arctic with abnormal late fall heat. Image source: Earth Nullschool.)

And though these warming events have been widely reported in climate media, what has not been reported is the fact that a pair warm storms similar to the one that hammered sea ice and brought North Pole temperatures to above freezing during late December of 2015 were also the triggers for the present Arctic Ocean warming event.

Such intense warm air invasions can have a dramatic impact on sea ice. According to NASA, last year’s late December warm storm event resulted in considerable ice thinning and melt over the critical sea ice region surrounding the North Pole. Ice in the Barents was reduced by 10 percent. Sea surface temperatures in some locations jumped to 20 degrees (F) above average. And throughout the month of January, there was little rebuilding of sea ice into the recently melted regions.

(A recent NASA study found that warm storms can have a serious impact on sea ice. And for both 2015 and 2016, this appears to be the case.)

This year’s warming event was also accompanied by a storm running north out of the Barents. On November 14, a 955 mb storm ran directly up through the Fram Strait. It ushered in warm, moist winds from the south which then spread northward over the Central Arctic — bringing with them above freezing temperatures. On November 16, a 966 mb storm crossed over Kamchatka. It subsequently weakened. But it still possessed enough oomph to pull in a strong plume of warmth and moisture as it entered the Arctic Ocean near the region of the East Siberian Sea. And the result has been a flood of warm air coming in from the Beaufort and East Siberian Sea to meet with the similar onrush coming from the Barents. The result is the huge Polar heat spike that we see today.

Following a very warm October, this is a kind of insult to injury situation for the sea ice. And though temperatures are expected to fall back a bit over the coming week in the High Arctic, atmospheric and ocean conditions running into December seem to favor the potential for more warm air influxes to this fragile climate zone.

UPDATE: On November 19, it had become apparent that significant sea ice losses were ongoing in the Arctic. According to the JAXA sea ice monitor, about 140,000 square kilometers of sea ice had been lost over the period of November 16 through 18. As Arctic Ocean ice typically freezes quite rapidly during November, such counter trend losses are highly extraordinary. Now, sea ice in the Arctic, according to JAXA is 995,000 square kilometers below the previous record low set during 2012.

NSIDC shows similar losses in the sea ice extent monitor for the period of November 16-18. In total, 170,000 square kilometers of ice has been lost over the three day period and the total departure from the previous record low in 2012 is now 702,000 square kilometers.

These losses are quite extensive and, in many ways, are worse that those that occurred following the December 27, 2015 warm storm event.

FINAL UPDATE: On Sunday, November 20th, the JAXA monitor bottomed out at 1.1 million square kilometers below the previous record low set in 2012. This is one of the most extreme departures below previous record lows ever recorded. To put it in perspective, the maximum difference between 2007 and 2012 at end melt season was around 900,000 square kilometers. So the November loss is very, very significant — especially when one considers that, for five days, November basically behaved like summer melt season.

With high pressure taking hold over the Arctic, clear skies are allowing some of the excess heat to ventilate out into space. As a result, it is likely that we’ll see the tremendous gap start to close over the next 7 days. However, GFS model runs still show the Arctic ranging between 3 and 6 C warmer than average over the period. So this trend back toward baseline will tend to be flagged by all the extra heat in place. In the 7-10 day period it appears that more warm wind and moisture delivery to the Arctic Ocean will again set up through the Barents. But the next potential heat spike does not appear to be as extreme as the event which occurred on November 14-19.

We’ve probably never seen weather like what’s being predicted for a vast region stretching from the North Atlantic to the North Pole and on into the broader Arctic this coming week. But it’s all in the forecast — an Icelandic low that’s stronger than most hurricanes featuring a wind field stretching over hundreds and hundreds of miles. One that taps warm tropical air and hurls it all the way to the North Pole and beyond during Winter time. And it all just reeks of a human-forced warming of the Earth’s climate…

Freak North Atlantic Storm Featuring Extremely Low Pressures

Sunday afternoon, a powerful, hurricane force low pressure system was in the process of rounding the southern tip of Greenland. This burly 960 mb beast roared out of an increasingly unstable Baffin Bay on Christmas. As it rounded Greenland and entered the North Atlantic, it pulled behind it a thousand-mile-wide gale force wind field even as it lashed the tip of Greenland with Hurricane force gusts. To its east, the storm now links with three other lows. Lows that are, even now, drawing south-to-north winds up from a region just west of Gibraltar, on past the UK, up beyond Iceland, over Svalbard, and into the Arctic Ocean itself.

(GFS forecasts predict a storm bombing out between 920 and 930 mb over Iceland by Wednesday. It’s a storm that could rival some of the strongest such systems ever recorded for the North Atlantic. But this storm’s influence is unique in its potential to shove an unprecedented amount of warm air into the Arctic. A warm storm for the Arctic Winter time. Image source: Earth Nullschool.)

Regardless of peak strength, the expected storm is predicted to be both very intense and wide-ranging as both model forecasts feature numerous lows linked in chain with a much deeper storm center near Iceland. Among these and further north, two more strong lows in the range of 965 to 975 mb will round out this daisy chain of what is now shaping up to be a truly extreme storm system. The Icelandic coast and near off-shore regions are expected to see heavy precipitation hurled over the island by 90 to 100 mile per hour or stronger winds raging out of 35-40 foot seas. Meanwhile, the UK will find itself in the grips of an extraordinarily strong southerly gale running over the backs of 30 foot swells.

Warm Winds to Force Above Freezing Temperatures For the North Pole

(By early Wednesday, temperatures at the North Pole are expected to exceed 1 degree Celsius readings. Such temperatures are in the range of more than 40 degrees Celsius (72 degrees Fahrenheit) above average. Image source: Earth Nullschool.)

All along the eastern side of this storm, powerful warm winds are expected to funnel northward. Originating along the 35 degree North Latitude line west of Spain, these winds will force a train of warm air and moisture pole-ward ahead of our storm. The winds will rush up over a very riled North Sea, they will howl into a far warmer than normal Barents, and they will roar on past Svalbard — finally turning as they pass beyond the North Pole.

These winds will bring with them extraordinarily warm temperatures for the High Arctic region during Winter time. By Wednesday, the North Pole is expected to see temperatures in the range of 1-2 degrees Celsius or 41-42 degrees C above Woods Hole and NASA baseline Winter-time temperatures (73-75 degrees Fahrenheit above the normal daily temperature of -40 F for a typical Winter day). Such an extreme departure would be like seeing a 120 degree (Fahrenheit) December day in my hometown of Gaithersburg, MD.

NCAR and reanalysis data for the North Pole at this time of year put daily averages in the range of -30 C (-22 F) and -20 C (-4 F) respectively. Taking all these measures into account, it appears that we’ll be seeing temperatures in the range of 36-72 degrees above normal North Pole readings for late December, depending on which baseline you use.

By any yardstick, these are extremely warm and likely record readings for the North Pole. Winter Temperatures have only approached the freezing mark on one previous occasion in the NCAR data record. And the predicted temperatures for Wednesday appear set to surpass this odd record. Needless to say, a 1-2 C reading at the North Pole during late December is about as odd as witnessing Hell freezing over. But, in this case, the latest wave of warmth issuing from a human-driven shift toward climatological hell appears to be on schedule to arrive at the North Pole by Wednesday.

“I contacted a team of climate scientists at the University of Washington who maintain a fleet of weather monitoring equipment near the North Pole. James Morison, the principal investigator of the North Pole Environmental Observatory, said he’s “never heard of” temperatures above freezing in the wintertime there. Looking closer at the weather data, it appears this event is in fact unprecedented during the time period from late December through late April”

(The Arctic region as a whole is expected to experience a [frankly quite insane] temperature anomaly in the range of 4 degrees Celsius above average by January 3rd of 2016. Note the broad regions over Northern Canada, Siberia, and the Arctic Ocean that are predicted to experience temperatures in the range of 20 degrees Celsius above the already hotter than normal 1979 to 2000 baseline readings. For some areas — particularly in Northern Canada — this will mean near or even above freezing temperatures for tundra and permafrost zones in the depths of Winter. A set of conditions that has serious implications for permafrost thaw and related carbon store feedbacks. Image source: Climate Reanalyzer.)

The deep, northward-driving synoptic pattern associated with both powerful high Latitude storms and warm winds is only something we’ve begun to see during recent years. The warming polar environment itself generates weaknesses in the Jet Stream which tends to allow these warm air invasions. In addition the warming oceans — which hold heat for longer than land masses — generate pathways for warm air invasions of the Arctic during Winter time. The Barents Sea, for example, has been particularly warm during recent years which has resulted in numerous warm wind invasion events issuing northward over Svalbard and regions eastward during recent years.

A final ingredient to this highly altered weather pattern appears to be a cooling of the sea surface in the North Atlantic just south of Greenland. This cooling has been set off by an increase in fresh water melt outflows from Greenland as glacial melt there has accelerated concordant with human-forced warming. The cool pool of glacial melt water south of Greenland has aided in the generation of a dipole featuring cool air to the west, warm air to the east. This year, warm air has tended to flow northward over Spain, the UK, and along a region between Iceland and Scandinavia. During the Winter of 2015-2016, this warm air slot has also been the breeding ground for very unstable weather and a number of powerful storm systems.

(It’s an El Nino year. But despite a climate feature that would typically strengthen the Jet Stream, what we see is another Arctic warm air invasion reminiscent of the recent polar vortex collapse events of Winters 2012 through 2014-2015. Note that the region of coldest air, which would typically tend to center over the North Pole has been driven south toward Greenland and Baffin Bay. A pattern that we’d expect concordant with world ocean warming and Greenland melt as a result of human-forced climate change. Image source: ECMWF.)

These are influences we see now. Ones that are impacting both the current powerful storm over Iceland and the unprecedented surge of warm air that is now preparing to invade the High Arctic. And though El Nino likely also played a part in the shifting of the storm generation zone toward Iceland, the far northward propagation of warm air into the Barents and High Arctic along with the extreme strength of the predicted storm are both likely new features of an overall altered pattern. What we witness here are both climates and weather features changing before our eyes in the form of what to us may seem a freak event — but what is actually part of a dangerous transition period away from the stable climates of the Holocene.

UPDATE: ECMWF model runs now predict an extraordinarily strong 920 mb low striking Iceland by Wednesday. With GFS model runs coming into agreement, the certainty of this extreme forecast intensity increases. NOAA’s Ocean Prediction Center now has an updated forecast of 90 knot winds for the region in conjunction with this very impressive storm system.

Finally, as the Washington Post indicates in this excellent article, though some scientists are increasingly concerned that current powerful North Atlantic storms have a climate change influence, others remain unconvinced. For my own part, and based on continued observations of the weather data, model attribution studies, sea surface temperature, and glacial melt indicators, I believe there is a strengthening case for climate change attribution in the instance of more frequent, intense North Atlantic storms and especially in the recent very frequent Arctic warm air invasion events. In addition, it will unfortunately take years-to-decades for the institutions of modern science to come to a consensus on this and other climate change related issues. Given that events are now likely in play that will generate rapid changes to global and, in particular, North Atlantic weather patterns, it is impractical to wait for a scientific consensus to develop before reporting on these emerging issues. Waiting, at this time, would be irresponsible as it would result in a general lack of awareness of the overall threat.

To paraphrase Dr. Jennifer Francis — at this point it is not practical to wait for us to achieve perfect knowledge. And, in fact, we have more than enough indicators at this time to show that something is quite dreadfully wrong.

SECOND UPDATE TUESDAY, DECEMBER 29

THIRD UPDATE 12:36 AM EST, WEDNESDAY, DECEMBER 30:

As of early Wednesday morning temperatures at the North Pole had risen to 1.1 C or 34 degrees F representing the highest temperatures ever recorded at the North Pole for this time of year and the first time this region of the high Arctic has experienced temperatures substantially above freezing during Winter.

(1.1 C reading at the North Pole by Midnight, EST is a historic high temperature for the, what should be frigid, top of our world. It’s also yet one more bit of evidence showing that global weather is now in the process of going far off-kilter. Image source: Earth Nullschool.)

Slate on Extreme Weather (It’s worth noting that the storm causing extreme weather in the Central US is not the same one that’s bombing out over Iceland and driving this severe polar warming event, though these storms are certainly both part of the same odd overall weather pattern.)

Special Mention to JDAllen and the Arctic Sea Ice Blog (I just became aware they began a discussion on the topic of unprecedented Arctic warming on December 26. ASIB deserves mention for their unfailing monitoring of the Northern Hemisphere sea ice and cryosphere as well as for their extraordinarily informative discussions.)

A vast swath of sea ice that painstakingly formed as somewhat cooler conditions had finally settled in near Svalbard and Frans Joseph Land in the Barents Sea was shattered yesterday as a powerful, heat-laden Arctic cyclone screamed up out of a rapidly warming extreme North Atlantic.

The storm originated west of the Norway coastline where, in recent years, a repository of exceptionally warm water has collected. This near-Arctic and Barents Sea warm pool has resulted in numerous effects including a forced recession of sea ice by hundreds of miles during winter time as well as providing impetus for various anomalous heat waves in Scandinavia in recent years.

This time, the heat pool was the genesis for a powerful storm that delivered an intense package of early season warmth to a section of sea ice drifting in the North Barents Sea region.

Warm Storm Impacts

In the above image, provided by NASA’s LANCE-MODIS sensor, we can see a 250 mile section of sea ice that had extended out into the Barents Sea over the past few weeks during a cooler period as warmer conditions shifted to the Laptev, East Siberian, and Beaufort Seas. The date of this shot is April 16. To the lower left is the tip of Svalbard. Upper left is the far edge of Frans Joseph Land. Another few hundred miles to the right of far right frame is Northern Norway.

The storm, for now is off frame.

Now on April 17, we can see the storm center in the far left frame near the tip of Svalbard. At this point, the storm has bombed out to an extraordinarily powerful 950 mb low, packing 60+ mph winds. In its upper quadrant, it carried with it temperatures ranging from 10 to 20 C above typical seasonal averages. Perhaps more importantly, through cyclonic forces it pumped waters that were up to 5 C above average temperature up from the depths and into the ice pack. This kind of cyclonic Ekman Pumping, in recent years, has had an increased potential to rapidly reduce sea ice due to warmer surrounding water conditions and warmer waters at depth.

Note that rapid sea ice disintegration is already involved in the wake of this severe Arctic Cyclone.

Now, today, on April 18, we can see that in the aftermath of this powerful Arctic Cyclone there is very little contiguous sea ice left. What remains is what in sea ice parlance can be termed nilas — very thin and diffuse ice of 0-10 centimeters in thickness. Note that the entire 250 mile zone is completely involved in this very visible ice loss and that such losses continue on past Frans Joseph Land and into the Kara Sea.

Further Implications for the 2014 Melt Season

Melt season in the Arctic is now well involved. In addition, we have numerous weaknesses in the Northern Hemisphere Jet Stream that continue to funnel much warmer than average air over the Arctic Sea Ice. Alaska, Siberia and the Barents all continue to see strong warm air impulses that progress well into the zone covered by sea ice.

Today, according to GFS model measures for the zero hour, average Arctic temperatures are 2.24 C above the, already warmer than normal, 1979 to 2000 average. This is a rather high spike for spring, when Arctic temperatures typically start to settle back down after seeing high levels of global warming associated heat amplification during winter time.

The excess heat had already pushed Arctic sea ice extent measures down to near record lows as of April 17. According to NSIDC, extent measures had fallen to 13.9 million square kilometers yesterday, the second lowest level in the measure. With full effect from the recent intense storm not yet fully realized, it is possible that impacts in this region alone could reduce total values by at least 100,000 square kilometers.

(Arctic Sea Ice Extent Second Lowest on Record for April 17. Data Source: NSIDC. Image Source: Pogoda i Klimat.)

Yet one more major blow to sea ice from a powerful warm storm type system. And, in this case, with melt season progressing rapidly and with so much heat already shifting into the Arctic, it is highly unlikely that this zone of newly dispersed ice will see much in the way of recovery over the coming weeks.

The weather models are all in agreement, an Arctic Cyclone is predicted to form over the Beaufort and Chukchi Seas tonight and tomorrow, then strengthen to around 980 millibars as it churns through a section of thin and broken sea ice. The storm is predicted to last at least until Saturday and is expected to deliver gale force winds over a broad swath of thinning sea ice throughout much of its duration.

The fact that this particular storm is forming in late summer is some cause for concern. The sea ice has been subjected to above freezing temperatures for some time. Melt ponds have increasingly formed over much of the Arctic and, since late June, most of the precipitation falling on the Arctic has been in the form of rain. The central ice pack is in complete chaos, with extensive thinning and fracturing surrounding a wide arc near the North Pole and a broad melt triangle full of broken ice and patches of open water extending far into the Laptev Sea. Further, the long duration of sunlight falling on the ice surface and penetrating into the ocean layer just beneath has likely warmed waters below the cold, fresh layer near the ice.

As the storm passes, its strong winds and cyclonic circulation have the potential to dredge up this warmer water and bring it in contact with the ice bottom. Such action can rapidly enhance melt, as we saw during the Great Arctic Cyclone of 2012. Since the brine channels are all mostly activated (with much ice in the region now above -5 degrees Celsius) Cyclonic pumping during storm events like this one can transport sea water directly through the ice to increase the size of melt ponds, to break, or to even disintegrate ice flows.

It is important to add the caveat that this particular storm in not predicted to be quite as long or as strong as the Great Arctic Cyclone of 2012 which, in its first week, coincided with a loss of 800,000 square kilometers of ice. But Arctic weather is nothing if not unpredictable and this particular event could just as easily fizzle as turn into an unprecedented monster.

That said, a number of concerning conditions have emerged just prior to this storm that may result in an enhanced effect on the ice. The first condition is that large sections of the Beaufort, East Siberian and Chukchi Seas are covered in thin, diffuse and mobile sea ice. These conditions are clearly visible in the surface shots provided by NASA/Lance-Modis:

In this section, as in other broad stretches of the Beaufort, the ice is reduced to a kind of slurry in which, as Neven over at the Arctic Ice Blog notes, the individual flows are completely degraded and difficult to make out. This slushy region is in direct contact with a region of mostly open water. Such areas of de-differentiated ice are likely to show greater mobility and enhanced wave action during storms, which puts them at risk of more rapid melt.

Another somewhat ominous note in advance of this storm is a rise in Arctic Ocean temperature anomalies over the past couple of days. NOAA’s surface temperature measure indicates a spreading pool of warmer than normal surface ocean conditions throughout the Arctic. In the region this storm is predicted to most greatly affect, the storm will have the potential to bring such warmer than normal surface waters into more consistent contact with the ice through the mechanical action of waves and by activating the brine channels in the ice. Further, a large pool of much warmer than normal surface water in the Chukchi Sea is likely to be driven deeper into the ice pack where it also may enhance melt.

In general, there’s quite a bit of atmospheric and ocean heat energy for this storm to tap and fling about. Not only is the surface ocean warmer than 1971-2000 base temperatures, but most continental land masses surrounding the Arctic are showing highs between the mid 60s to upper 80s and lows between the 40s and upper 60s.

ECMWF model forecasts show the storm tapping some of this energy in advance of intensification, with a tongue of warm Alaskan and Canadian air being drawn into the storm at the 5,000 foot level late Monday and early Tuesday. Directly opposite, Siberia and Eastern Europe have hosted very warm air masses with daytime surface temperatures above the Arctic Circle reaching the upper 80s consistently over the past week. This warmth also encroaches just prior to storm intensification.

Added heat energy injected at the surface and at the upper levels will ensure that the vast majority of precipitation during this event emerges as rainfall.

Broader effects of this storm could be quite significant. The US Navy’s CICE models are showing a greatly enhanced ice motion throughout the duration of this storm as its counter-clockwise circulation is predicted to dramatically increase the movement of the Arctic’s remaining thick ice toward the Fram Strait. The Navy’s thickness monitor also shows a jump in ice thinning and dispersal throughout the ice pack over the duration of this event. In particular, the back end of remaining thick ice north of the Canadian Arctic Archipelago is mashed like a tube of tooth paste in the model run, pushing a broad head of ice toward the Fram. At the same time, a large section of Central ice, earlier thinned by PAC 2013, is projected to rapidly expand and further thin under the influence of this storm.

Note the rapidly expanding melt wave from the North Pole to the Laptev that appears in the final frames of the run below:

So it appears we have a short duration but relatively high intensity Warm Storm event predicted to have broad-ranging effects from the Beaufort to the Central Arctic. An event that could have impacts similar to those of the Great Arctic Cyclone of 2012. Should such circumstances arise, it begs the question — is the Beaufort a region that is more likely to spawn these kinds of storms come late July through early to mid August? The region is now surrounded by increasingly warm continents. The observed weakening of the polar Jet Stream by 14% has resulted in a much greater transport of heat to the high continental boundary, as evidenced by a broad swath of heat-waves ringing the Arctic above the 60 degree North Latitude line. The increasingly thin Beaufort ice jutting out into this crescent of continental heat may well be the ignition point for major atmospheric instability, powerful storms and related heat transfer. Something to consider should these kinds of late season ice melters recur on a more frequent basis.

To this point, a new naming convention has been proposed over at the Arctic Sea Ice blog for summer storms that greatly impact the ice. Preliminary standards have been set for storms with a central pressure lower than 985 mb (at peak intensity) and a duration longer than 4 days. Suggestions for storm titles include traditional Inupiat names from this region or even the use of the names of prominent climate change deniers (My opinion is that both calling attention to major Arctic melt events and how climate change deniers have attempted to cover such events up would be an excellent use of such a convention, but I may be out-voted).

In conclusion, the potential arises for the first named Arctic Cyclone to result in dramatic melt and weakening of sea ice throughout the upcoming week. This potential heightens the risk for 2013 to be another record melt year and so we will continue monitoring the storm’s development closely for you.

Earlier this week, a moderate-strength Arctic Cyclone formed near Svalbard. Since that time it has persisted even as it drifted into the Laptev sea as a 1000 mb low today. Now, according to forecasts, the storm threatens to remain in the region for at least the next ten days, deepening to as strong as 980 mb and chewing into a region of sea ice that has been consistently weakened by storms since late May.

If you’ve followed this blog and feel you’ve heard this story before, it’s because you have. PAC#1 formed in late May and churned through the central sea ice all throughout June, creating anomalous thinning of a region near the North Pole and on toward the Laptev sea. By early July, the storm had finally petered out, but not after leaving behind a wreckage of thinned and broken sea ice.

Now, it appears a second storm (PAC 2013 #2) is set to churn through the same regions so drastically impacted by PAC 2013 #1, this time lasting for at least two weeks.

The above image shows a strong 980 mb PAC 2013 #2 over the Beaufort Sea on July 24th. Current model runs show the storm moving back and forth over the Central Arctic, Beaufort and East Siberian Seas until at least July 29th.

Warm Storm Takes Hold

As sea ice is much thinner and as atmospheric and ocean temperatures are much warmer, it is likely that a new Persistent Arctic Cyclone will have even more obvious and far-reaching effects than the one we witnessed in June. Average surface atmospheric temperatures throughout the Arctic are above the temperature at which ocean water freezes and almost all regions show temperatures above 0 degrees Celsius. So precipitation in these storm events is more and more likely to fall as rain.

You can view how much the Arctic has warmed in the composite weather map below:

Note the large pulse of 78-86 degree (Fahrenheit) weather (24-30 degree Celsius) pushing all the way to the Kara Sea near Archangel and points eastward. Meanwhile, 40-50 degree (Fahrenheit) temperatures have become common in areas near Svalbard, the extreme north coast of Greenland, and even during the daytime over some sections of the Beaufort (not visible in the current shot above). We can also see a number of wildfires raging in the heatwave stricken region of Arctic Russia (fire sites on the map are indicated by vertical black lines with squiggles on top).

Overall, temperatures over the Arctic Ocean have averaged 1-3 degrees Celsius above normal. With most of the summer spent in cloudy, stormy conditions that usually lead to cooler weather, this year is highly, highly anomalous. What we have, instead, are warm storm conditions.

With all this heat in place, wet, rainy precipitation is much more likely to fall over areas of the Central Arctic underneath the new storm. As water carries more heat energy than air, a warmer than freezing rainfall over the ice sheet is a powerful melt enhancer. In addition, associated winds are likely to further shatter and disassociate ice beneath it. Eckman pumping forces will also be more likely to access warmer waters beneath the colder, fresher layer that tends to protect the ice. This is due to the fact that a constant sunlight has now streamed through the ice for two and half months running. This long duration sunlight is likely to create a warmer water layer in a range of 40-70 feet beneath the surface. A passing storm of moderate to strong intensity will likely be able to access this warmer layer and transport it to the surface where it can do work melting ice.

A somewhat stark example of what a warm storm can do to thin, fragile sea ice is also now plainly visible via APL’s North Pole Camera #2. Even since yesterday we can see that melting has rapidly advanced around the camera as it now rests in a deepening and expanding melt lake stretching far about in all directions:

From this shot, only a small band of remaining snow cover now surrounds the buoy in the foreground. It also appears that the camera itself is now sitting in the water. It is worth noting that this melt lake currently rests on ice that is probably between 1 and 2 meters in thickness. But the waters now covering the ice are darker, absorbing more direct and indirect sunlight even as the above-freezing melt lake slowly bores down into the ice. If the Eckman pumping forces engaged by this storm are also bringing warmer waters up from the depths, the ice near this camera is suffering melt from both above and below.

Though the current picture shows somewhat sunny weather, conditions near the camera have been mostly stormy for the past three days. It is likely that storm conditions will soon return as this region is mostly engulfed in cloud.

Major sea ice monitors now show ice area, extent and volume all falling rapidly. Sea ice extent, according to NSIDC is at about 7.8 million square kilometers — or 4th lowest on record. Cryosphere Today also shows sea ice area tied for 4th lowest on record with about 5.5 million square kilometers of sea ice area remaining. Area losses in this measure have been particularly cliff-like with nearly 400,000 square kilometers lost in just two days. Similar losses over the next 5-6 days would bring the monitor into new record low territory. By mid June, PIOMAS showed the sea ice volume measure running at about 3rd lowest on record with rapid losses ongoing since late May.

Though these values still remain above record lows, there is a huge amount of heat energy moving around in the Arctic. Earlier this year, the sudden amplification of the heat in May led to the fastest snow melt on record. Snow cover at the end of April was 9th highest. By the end of May, snow cover levels had plummeted to 3rd lowest. The fact that the Arctic is capable of such dramatic swings is clear proof that the heat balance there has reached highly unstable levels. It is for these reasons that we must remain alert for the potential of rapid ice loss as July transitions into August.

Despite a slow early May sea ice melt (in contrast to a racing snow melt), rates of loss have been near record levels throughout June and July of 2013. Given this break-neck melt pace and a state of continued fragility throughout the ice pack, risk remains high that one or more measures will see new record lows come September. Sea ice is now also very highly dispersed making it even more vulnerable to melt and disruption. The most recent Crysophere Today shot shows broad regions where sea ice concentration is now 60% or less.

With such broad areas of ice so vulnerable and exposed, any further thinning, melt and dispersal caused by the re-emergence of a warm storm is likely have strong impacts with the potential to dramatically affect final melt totals.

Well, it’s official. PAC 2013 has yet to give up the ghost. After transitioning to the Canadian Archipelago, it has now formed a trough composing three low pressure centers that roughly straddles Greenland, Baffin Bay, and the thickest sea ice. At this point, the storm is nearly one month old (with a formation date around May 21-26). Lowest pressures appear to be around 990 mb, but the entire region is covered in rough weather and clouds.

A look at the heat map shows the storm pulling in warmer air from the Alaskan side of the Arctic and from regions around it. This extra energy has given it enough to fuel multiple lows for an extended period. As a by-product, many regions over the Central Arctic are now above freezing. Areas near the low pressure centers still show temperatures in the range of 0 to -3 Celsius. But a broad swath of above-freezing temperatures are now under the circulation of this, rather large, storm.

On the map, we also notice areas of high heat concentration centered over Scandinavia, Central Siberia, Alaska, and just West of Hudson Bay. These regions of heat are both potential launching pads for more warm air invasions of the Arctic as well as feeding sources for our storm, should it continue.

And, according to forecasts, we can find that this storm isn’t done by a long-shot. ECMWF model runs show it forming troughs with numerous low pressure cells and chewing through large portions of the Arctic all the way through to July 1. Seems we were right to caution against an end to PAC 2013 in this earlier blog.

A very interesting example is the ECMWF forecast for June 27th when PAC 2013 forms a sprawling trough from the East Siberian Sea to Baffin Bay to Greenland to the Kara. It is a trough composed of not one, not two, but at least six separate low pressure cells. The forecast for tomorrow through much of the model run shows similar configurations with daisy chains of storms linked by a trough swirling along through the Arctic.

These model runs would seem to indication very stormy conditions not only for the Central Arctic, but for the periphery as well.

The ‘Warm’ Arctic Storm Begins to Emerge?

With temperatures rising to above freezing in the Central Arctic Basin and with storms projected to persist at least until July 1rst, we may receive an unwelcome glimpse of the ‘Warm’ Storm described here. Previously, I had speculated that ‘Warm’ Storm conditions would be present with moderate-to-strong cyclones persisting in the Central Arctic at a time when air temperatures ranged from 0 to 6 degrees Celsius. As we can see from the temperature map at the top of the post, we are not far off from that threshold now. And with heatwaves popping up around the Arctic there is more than enough warmth to push Central Arctic temperatures higher over the coming days and weeks.

Over at the Arctic Ice Blog (read it, join it, follow it, chat on it — you will learn boatloads), expert posters Wayne and R. Gates have noted that while clouds block direct sunlight, they can act to trap long-wave radiation. R. Gates had also linked a recent scientific study which showed that cloudy conditions from March to May enhanced rather than inhibited melt. The energy of this long-wave radiation would transfer directly to ice and ocean, so atmospheric temperatures would not be directly impacted. But more heat content in the waters and ice, overall, might be providing some of the extra kick that ECMWF appears to have missed. Another recent study by Edward Hanna found that low level clouds helped to increase the record Greenland ice sheet melt of 2012 (study here) by trapping heat near the ice. So the overall effect of clouds in cooling is less certain than one would think at first blush.

Another source of this extra heat may be via the ocean itself. As noted in previous posts, cyclonic action creates a kind of pumping force (Ekman), that can pull water up from the ocean’s depths. In the Arctic, the surface layer is cold. But underneath lies a layer of warm water fueled by the inflow from oceans surrounding the Arctic (primarily the Atlantic). As commenter Johnm33 noted, once a strong inflow of upwelling water is established, it is possible that yet more warm water is being drawn into the deep Arctic Ocean from the Atlantic. If this warmer inflow was pumped to the surface, it would add to atmospheric heat beneath the storm.

Lastly, the atmosphere, via high amplitude waves in the Jet Stream is now also providing its own source of heat by dredging deep into the lower latitudes and pulling warmer air up into the Arctic. So far this summer, we have seen record heat waves in both Scandinavia and Alaska. These heat waves were caused by persistent blocking patterns that injected heat into these Arctic locations. Scandinavia saw temperatures in the 80s, Alaska saw temperatures rocketing into the upper 90s. The Jet Stream configuration allowing for these hot air injections at these locations still persists and are plainly visible on the current Jet Stream map:

Note the large wave in the Jet Stream (and associated warmer air) now riding up over Alaska and deep into the Beaufort, Chukchi, and East Siberian Seas. Another pulse is visible lunging up through Scandinavia. A third, though less southwardly linked, pulse is also now rising over Eastern Siberia. These extraordinarily high amplitude waves all cross far beyond the Arctic Circle. An atmospheric condition that is anything but normal and one that is also continuing to supply warmer air to the Arctic environment, even one covered by a storm that would normally substantially cool the atmosphere there (for more information on how snow and ice melt in the Arctic is enabling these high amplitude Jet Stream waves, take a look at some of the work of Dr Jennifer Francis). Instead, as the discrepancy with ECMWF predictions and surface observations shows, we have temperatures that are only .5 to 1 degree C cooler than average under the storm (they should be about 3-7 C cooler) and much, much warmer conditions surrounding it.

A Warm Storm persisting in the Central Arctic for long periods is a potential nightmare scenario for sea ice melt. Currently, we have warming conditions in the Central Arctic, a spate of record heat-waves at the periphery in places like Alaska and Scandinavia, a mangled Jet Stream that keeps pumping warmer air into the Arctic, and a storm that is now projected to persist until at least July 1rst. So we now have to consider at least the temporary emergence of the Warm Storm to be a possibility going forward.

Impacts to Sea Ice Still Ongoing, Likely to Ramp Up

A substantial thinning and chopping up of the sea ice is now apparent in all visible (when you can see through the clouds), concentration, and thickness monitors. Now, a wasteland of thinned, shattered and broken ice is visible in a swath from Svalbard all the way to Wrangle Island near the Bering Strait. A comprehensive graphic summary of these impacts is provided below:

The current image, provided by the US Navy is a stark contrast to conditions seen at the end of May. This thickness measure shows a long ‘claw’ of much thinner ice reaching all the way in to the Central Arctic and encompassing the North Pole. This graphic reveals very poor Central Ice thickness conditions for mid-to-late June.

Uni-Bremen has been providing consistent confirmation of ice damage and fragmentation due to the Ongoing Arctic Storm for nearly two weeks now. Here’s the most recent concentration monitor showing the broad swath of broken ice.

And Cryosphere Today, which is less sensitive than the other monitors shows low ice concentrations stretching from Svalbard to Wrangle Island.

Overall, should PAC 2013 continue to warm even as it persists, it should have ever-greater deleterious effects on the Central Arctic sea ice as mid-to-late June transitions into July. The US Navy thickness forecast shows ongoing thinning and fracturing in this region all the way through June 28th. One interesting feature of note in this forecast is that it appears a substantial section of ice will be separated from the main pack and stranded in the Kara Sea if current trends continue through early July.

So, apparently against all odds, PAC 2013 continues and, even worse, shows risk of beginning a transition to a ‘Warm’ Storm in the Central Arctic. Should this trend remain in effect, increasingly visible damage to the central ice is likely to become ever more apparent as June turns to July.

This past week has hosted a variety of extreme and unprecedented weather events. In the US, storms pummeled a region from the Dakotas to the US East Coast while Colorado suffered its worst wildfire ever recorded, the third time such a dubious record has been broken in the past year. And, in the Arctic, a persistent cyclone (PAC 2013) ended its 3rd week of ice thinning as Greenland melt blew through the usual summer maximum with hardly a pause.

US Derecho, Severe Storms

A storm system that spawned numerous severe thunderstorms, high wind events, hail, heavy rain, and sporadic tornadoes swept through a broad swath of the northern, central, and eastern United States from Tuesday through Thursday. Major power outages were reported over this broad region and, sadly, one death occurred when a little boy lost his life to falling trees in Virginia on Thursday.

This combined derecho and severe thunderstorm event, though less severe than last year’s June 29th ‘Hurricane over Land,’ still resulted in major impacts. According to Jeff Masters, from Weather Underground:

NOAA’s Storm Prediction Center (SPC) logged 376 reports of damaging thunderstorm wind gusts in the 15 hours ending at 11:25 pm EDT Thursday night, and three of these gusts were 74 mph or greater. SPC is now acknowledging that Wednesday’s bow echo that traveled 600 miles from Indiana to New Jersey was a low-end derecho, with over 150 damaging wind reports. The most impressive thunderstorm winds from the derecho occurred in Wabash County, Indiana, where a “macroburst” produced winds of 90 – 100 mph across an area seven miles long and three miles wide, destroying three buildings and causing extensive tree damage. Total damage from the two-day severe weather outbreak over the Midwest and Mid-Atlantic will likely run into the hundreds of millions of dollars.

You can view the progression of yesterday’s derecho in the NOAA/National Weather Service radar sequence here:

Western Drought and Colorado Fires

Meanwhile, the western drought, still covering over 44% of the US, spawned the most damaging fire in Colorado history. Again.

The Black Forest Fire has now destroyed nearly 400 homes, killed 2 people, forced nearly 40,000 people to evacuate, and burned over 18,000 acres. Last year, the High Parks Fire and then the Waldo Canyon Fire each successively broke the record, set in 2002 for the most damaging fire in Colorado history. Now, just one year later, the Black Forest Fire has again taken the record.

Three record damaging fires in one year is anything but normal. But, according to climate forecasts, things are going to get much worse for Coloradans. According to this US Department of Agriculture study, under a ‘moderate global warming scenario’ in which Colorado temperatures rise by an additional 1 degree Celsius by 2050, the area burned by forest fires would increase by 2.8 to 6.6 times the current level.

Fuel for the Colorado fires is provided by an embedded drought which has persisted in the region since last spring. Unfortunately, a switch to mild La Nina conditions in the Pacific may indicate that the US drought is set to expand once more.

Droughts are also predicted to grow more severe for the southwestern and central US as global temperatures rise. And this projected increase in drought conditions not only has implications for increasing risk of fire, it also drastically impacts US food productivity.

Farmers already suffering from last year’s drought can still expect to face climate extremes over a large area of the US. And with La Nina increasing risks that drought will re-expand, it appears the beginning of a long era of damage to crops and increased risk of severe fire via the ratcheting effects of climate change is now starting to settle over the US.

Moving northward into colder climes we enter the epicenter of another ongoing tale of climate change tragedy. In this case, a Persistent Arctic Cyclone which has continued to batter and thin the northern polar sea ice has now entered its fourth week.

The storm is now a 985 mb low centered between Svalbard and the North Pole. Two smaller storms are now also incorporated into its larger circulation and are indicated by the two light blue circles on the map:

The storm continues to pull warmer air into the Central Arctic from the south. Now, much of the Arctic Basin is experiencing above freezing temperatures. Yesterday, Barrow Alaska, one of the coldest cities in the Northern Hemisphere, experienced a 65 degree high, about 26 degrees above average for this time of year.

The below weather map shows temperatures above the freezing point of sea water (-1.9 C) covering all but a few isolated locations. In one location on the coast of Siberia and bordering the Arctic Ocean, the temperature has risen to a balmy 27 degrees Celsius or about 81 degrees Fahrenheit.

Forecasts for the storm have tended to trend for it remaining in the Central Arctic at least until late next week. If these forecasts bear out, by next Friday we’ll begin talking about the month-long storm.

With the storm continuing for so long, it is forecast to really begin digging deep into the Arctic sea ice by next week. US Navy models continue to show major thinning in a broad swath from the Laptev Sea to the North Pole and creeping on toward Svalbard. Such projections show continued, dramatic and rapid thinning ramping up all the way through June 21rst. At this point, PAC 2013 begins to look more like the nightmare scenario I discussed in The Warm Storm blog and less like the strong thinning event we’ve witnessed thus far.

It is worth stating that we’ve never before witnessed a Persistent Arctic Cyclone thin the ice to any note-worthy extent during June. This particular storm is already unprecedented in its impacts and the fact that it continues and is projected to continue for at least the next ten days should be major cause for concern.

Simply put, the Arctic sea ice is in ongoing and deepening peril. Should these amazing thinning and melt values the Navy is predicting emerge next week, we’ll have to modify our ‘Ice Free Arctic’ prediction (currently at 10% for 2013) accordingly.

Meanwhile, a related warming and melt is now occurring in Greenland, may be set to challenge an extreme record 120 year melt seen just last year.

Greenland Melt Starting to Go Bonkers

Earlier this week, Greenland melt surpassed maximum summer melt values usually seen in mid-to-late July. Today, these melt totals proceeded to spike without hardly a pause.

Average maximum melt area for Greenland usually peaks at around 23% during mid-summer. By Friday, June 14th, about 27% of the Greenland ice sheet experienced melt. You can see this rapid and ongoing spike in Greenland melt in the graphic below:

Current melt coverage is still below last year’s record of near 100%. However, those values didn’t emerge until July and current melt is proceeding at a rapid enough pace to raise concerns that the 2012 record could be challenged this year.

Greenland melt is a major driver of extreme weather events. Melt has currently reached an average of 500 gigatons from the Greenland ice sheet annually. This level is already three times that observed in the 1990s. But melt rates are still rising over time. This massive and growing volume of melt water has already slowed the Gulf Stream and is likely playing a role in severe winters and springs in Europe.

Combined with sea ice erosion, which Dr. Jennifer Francis has implicated in a slowing of the Northern Hemisphere Jet Stream, Greenland melt is a powerful driver of the extreme weather we expect to see as climate continues to change.

Of these four events, three — the Colorado fires, PAC 2013, and amplified Greenland melt — can be directly attributed to a warming climate. The derecho, on the other hand, was likely made worse by a combination of alterations to the global jet stream, increased atmospheric heating, and increased water vapor pumping up the thunderstorms it spawned. Together they provide a context of climate change. One we are just starting to see emerge and one that will likely grow far worse should we not rapidly reduce our use of fossil fuels.

Yesterday, two commenters — Sourabh in this blog post and T.O.O. in this blog post — raised some very salient questions about 2013’s Persistent Arctic Cyclone (PAC). These commenters wanted to know how critical to melting is PAC 2013, is this the first time we’re witnessing thinning of the central ice due to a long-period Persistent Arctic Cyclone, and by ‘what conditions could the central ice be expelled from the Arctic Basin?’

I posted a short response to their comments here and here. But I wanted to take the time to explore their questions in greater depth. Hence, this blog post.

Long Duration Summer Cyclones Rare, But Not Unheard of

First, let’s take a look at the current PAC 2013, its forecast duration, and how it compares to other storms. For context, it is important to note that most cyclones in the Arctic basin last for 40 hours or less. By comparison, PAC 2013 began on about May 26th and has remained in the Arctic for about 16 days. Forecasts now show the storm persisting until at least June 21rst. If the storm lasts this long, it will have remained in the Arctic for 26 days.

It is worth noting that Arctic cyclones are a year-round phenomena. And that more numerous, though somewhat weaker storms, have been noted to appear from May to July. That said, the strongest, longest duration storms usually occur during winter and can last for three weeks to a month or more. During summer, Arctic cyclones are weaker, pack less of a punch, and usually don’t last as long as winter storms. What makes PAC 2013 and GAC 2012 exceptional is the fact that they were both strong, long duration storms occurring during summertime and that they occurred under conditions of record thin Arctic sea ice.

Overall, PAC 2013, though somewhat weaker than GAC 2012 at peak strength, is projected to remain in the Arctic for a very long time. And with lowest pressures rivaling that of a moderate-strength tropical cyclone, it should continue to have substantial impacts — both to Arctic weather and to sea ice.

New Event: Storms that Melt Sea Ice

The Great Arctic Cyclone of 2012 was also unique because it was the first storm to have a major impact on Arctic sea ice. Though researchers have tended to disagree over how pivotal the storm was in reducing ice to the record low values achieved during 2012, it is generally accepted that the storm melted at least 250,000 square kilometers of sea ice during early August.

The storm achieved this feat by mixing the surface ice with warmer waters lying just beneath. Wave action and cyclonic pumping of warmer waters from the depths provided a powerful force for thinning and melting the surface ice. Though no direct research on sea ice volume losses due to GAC 2012 has been published, CICE images before and after the event speak to a major thinning as a result of the 2012 Cyclone.

Note the large areas of ice thinned into naught by the storm as it plowed through the East Siberian, Chukchi, and Beaufort Seas. A region of central ice was also noticeably thinned during the storm.

We can, therefore, say with some confidence that it is the ice thinning forces of the storm which caused the loss of 250,000 square kilometers of sea ice attributed to its impacts. But we can also say that a visible and, as yet, undetermined volume of ice was also lost and that this loss substantially contributed to 2012’s record low status.

A similar situation is now present during PAC 2013. Substantial thinning is now visible in all the sea ice monitors, especially on the Russian side of the North Pole. But this event is different from GAC 2012 in that is occurring during June, a period of time in which the ice is thicker and more resilient. A period of time when air and water temperatures are relatively cooler. As a result, no where near as much in the way of sea ice area losses can yet be attributed to PAC 2013. I say ‘yet’ because this storm appears determined to stick around for the long haul. So we may see major area losses arise as a result of its action.

In any case, it is worth looking at before and after thickness maps to determine the level of damage caused by PAC 2013.

As is plainly visible from the above set of images, PAC 2013 has dramatically hollowed out the central sea ice. With at least another ten days of duration expected, we are still just in the preliminary phase of impacts. These should ramp higher as the days continue to progress. (Note, the last image was added on June 18th, two days prior to a possible cessation of the storm).

Both PAC 2013 and GAC 2012 are new events for the reason that they result in melt and weakening of sea ice. This is unprecedented because past storms did not generate measurable losses in summer (You can look at some of this research here and here). To the contrary, it was thought that the cloudier, cooler storms were generally protective. And this was true in a cooler climate. Now, strong storms have a potential to result in losses. And this new feature is an environmental condition brought about by human-caused climate change.

Is This the First Time We’re Witnessing A Summer Cyclone Thin the Central Ice in June?

Now that we have a little background on summer cyclones and how climate change has enabled them to both significantly thin and melt ice, we can confidently answer the question: is this the first time we’re witnessing a summer cyclone thin the central ice in June?

The short answer to this question is: yes.

In the satellite record, there is no precedent for a June storm melting and weakening the ice in the past. Though June storms have impacted and fragmented the ice before PAC 2013, this storm is the first powerful, long-duration event to have such a large, measurable melt effect in early summer. As noted above, past storms were thought to be defensive, resulting in a more resilient ice pack and less melt, overall, come end of summer.

In part, such widespread damage is due to the fact that the area currently influenced by the storm is so large — covering all of the Central Arctic. The other reason is the fact that the ice in this key region is supposed to be the most resilient to late summer losses. Instead, in early summer, we see damage and erosion.

Were the storm to end now, it would leave the central ice thinner and weaker to the assaults of late summer. But the storm hasn’t ended. It continues to churn and thin the ice even as temperatures rise.

It is possible that, if this storm lasts long enough, remains strong enough, and pulls in enough warm air, it could produce a large region of open water at the very center of the ice pack even as it shoves a large portion of the thickest ice toward the Fram Strait. Such an event would not only be unprecedented. It could be catastrophic.

Under What Conditions Could the Central Ice Be Expelled From the Fram Strait? Short Answer: Persistent, Warm Storm

So now we’ll address the nightmare scenario for this particular event. This expose is by no way a prediction. It is just an illustration of what the worst case, in this event, could look like. It is also, by no means, the only way we could lose all or most of the central ice. The ice, for example, could melt out under a sustained assault from the sun. The central ice could take a hit from a swift, powerful storm, then melt as warm air and sunlight moves in behind it. We won’t examine these and other cases. Instead, we’ll take a look at the worst case in the event of a long-lasting Persistent Arctic Cyclone that warms and churns throughout a good portion of summer.

The event could look something like this:

The Persistent Arctic Cyclone that emerged in late May continues on through June and into July. As the Arctic warms, more above freezing temperatures get wrapped into the storm. Eventually, much of the region it covers warms to a range of 0-6 degrees Celsius. Rain becomes a primary form of precipitation in the storm.

The added moisture, warmer cloud cover, and above freezing precipitation create a constant surface stress to the ice. Underneath, the constant churning pushes water temperatures above freezing due to an ongoing mixing of the cold surface layer with deeper, warmer waters. The combined result is an ice melting and thinning machine. By the end of June, a growing region of open water (concentration 20% and less) has emerged.

The open water is a breeding ground for powerful waves and a magnet for sunlight streaming down through periodic breaks in the clouds. This region of warmer water thrashes and bores through the ice as July advances, creating a pheonomena never before seen in the Arctic — a large, central region of open water surrounded by thinning ice. The result is ice edge melt occurring at the same time as central ice melt. From the cored out portion, an arm of open and or nearly open water begins to sweep around the Arctic, clearing away ice in its path. The arm extends to weakest areas of sea ice. A most likely candidate for this arm’s development is the Laptev Sea as there ice there has been weakest since start of melt.

These three factors would be devastating enough. But a fourth factor provides the coupe de grace: Fram Strait export.

The constant counter-clockwise motion of our warm storm has been shoving at the remaining thick ice anchored on Greenland and the Canadian Arctic Archipelago since early June. Increasingly, large volumes of thick ice are flushed out the Fram Strait. By end of June, as much as 10% of the thick ice has been exported. But this is just the beginning.

During late June and early-to-mid July, warm air invasions from the south have melted and thinned the Canadian Arctic Archipelago ice. Now thinning and fractures from this warming have advanced into the thick ice, weakening its anchor. During July, there is less resistance to the storm’s counter-clockwise motion so more and more thick ice ends up meeting its end through the Fram Straight.

By early August, the storm has lasted for an excessive period — nearly seventy days. But it still churns on, fed by an endless procession of storms and injections of warm, moist air from the south. In a final explosion of weather never before seen in the Arctic, much of the remaining thick ice is ejected, melted, or churned beneath a storm-tossed Arctic Ocean. By early September, the storm finally disperses, but little or no ice remains.

Conclusion

The above ‘Warm Storm’ scenario is pure speculation. We have no reason to believe the current PAC 2013 will last so long or will have such powerful effects. More likely, a still damaging but more moderate erosion of central sea ice combined with an enhanced Fram Straight export will occur. Should the storm last until the end of June, these damaging impacts will be more than enough to weaken the ice.

That said, should the storm last longer, then we will have an altogether unwelcome opportunity to test this ‘Warm Storm’ theory.

So we come at last, to answering the first question of our commenters:

How critical to melting is PAC 2013?

And the answer to this question will depend on the duration of the storm, its relative strength over time, how much warm air is injected into it over the course of its life-span, and how much warm water it is able to dredge up from beneath it. At the very least it has already played a major part in early season melt. Should it last for a long duration, the story of 2013 melt may well become wrapped up into that of this particularly anomalous storm.